Honked off at my 540i for the first time

[Mr._Graybeard]

Well, for a brief moment thoughts of my up-to-now dead-nuts reliable E34 commingled with gasoline and a match. I blew one of the trans cooler lines at the back of the engine ... then, while removing the fitting on the cooler, all the threads on the cooler nipple came off with it.

I've got the other fitting soaked with penetrating oil (gotta replace that line too, for sure) but I'm not sure I going to do any better. With the exposure to road moisture down there, it's a hothouse for galvanic corrosion. The belly pan might make it even worse.

I'm thinking of three options at the moment:

1: while installing the new lines on the cooler as is, try some teflon tape and see if the line fitting tightens down. There are some thread nubbins left on the nipple, so that might work. The pressure is only a little over a bar, but of course the coolant gets quite warm. And of course, that'll leave me wondering how sound and permanent the repair is.

2: pull the cooler and take it to a local machine shop where they might be able to weld on some new nipples or even hose barbs. I don't really see any need for hard lines there. I did the same thing with a trans cooler line on a Ford Taurus and it works just fine.

3: buy a new cooler from Kirt Koeller. It's in the ZF parts catalog on E38.org. I'll be sitting down when he quotes me a price.

I've wanted to change out the hoses for years, really, but I had a lot of concern about how the cooler would fare. So now I know the answer: not too well.

[Tiger]

You must have a manual tranny... Auto tranny in 540 doesn't have cooler line... nothing to the radiator.

There is Option 4... use quick epoxy as a thread locker... but you really do need to be able to tighten it... otherwise, forget it.

Use PB Blast... it is the only penetrading oil that really does the tough work...

I like option #2 the best but you got to hydraulic line shop... they can match everythign there. Even clamp you a new hose to your length with all the right fittings.

[h2oyo]

You must have a manual tranny... Auto tranny in 540 doesn't have cooler line... nothing to the radiator.

There is Option 4... use quick epoxy as a thread locker... but you really do need to be able to tighten it... otherwise, forget it.

Use PB Blast... it is the only penetrading oil that really does the tough work...

I like option #2 the best but you got to hydraulic line shop... they can match everythign there. Even clamp you a new hose to your length with all the right fittings.

My 95 540 had an transmission cooler on it when I did my change from auto to 6 speed. I do have the cooler if you need one. I can get it shipped out this Monday from work if you would like.
Johan

[Mr._Graybeard]

Sorry for the slow reply -- had to go make a dollar.

Option 5 -- a helpful soul comes along and offers a used cooler. I love it.

Johan, I'll PM you and we can work out the details.

Tiger, thanks too for the input. My wife and I were planning to drive out to Arizona this week in the 5er, but I don't think it's going to be ready. On the other hand, we didn't get stranded on a deserted Utah highway with a car spewing coolant. Life ain't perfect, but it's still good.

[Mr._Graybeard]

Hm, looks like the PM function is also out of commission. Johan, please email me at rinard (at) execpc (dot) com and we'll work out a deal. Thanks!